using FluentAssertions;
using FreeCode.Tools;
using FreeCode.Tests.Unit.Helpers;
using Xunit;

namespace FreeCode.Tests.Unit.Tools;

public sealed class FileReadToolTests : IDisposable
{
    private readonly string _tempDirectory = Path.Combine(Path.GetTempPath(), "free-code-tests", Guid.NewGuid().ToString("N"));
    private readonly FileReadTool _sut = new();

    public FileReadToolTests()
    {
        Directory.CreateDirectory(_tempDirectory);
    }

    [Fact]
    public async Task ExecuteAsync_ReadsExistingFile()
    {
        var path = Path.Combine(_tempDirectory, "sample.txt");
        await File.WriteAllTextAsync(path, "first\nsecond\nthird");

        var result = await _sut.ExecuteAsync(new FileReadToolInput(path), TestHelper.CreateContext());

        result.IsError.Should().BeFalse();
        result.Data.Should().Contain("second");
    }

    [Fact]
    public async Task ExecuteAsync_WithOffsetAndLimit_ReturnsRequestedSlice()
    {
        var path = Path.Combine(_tempDirectory, "sample.txt");
        await File.WriteAllTextAsync(path, "zero\none\ntwo\nthree");

        var result = await _sut.ExecuteAsync(new FileReadToolInput(path, offset: 1, limit: 2), TestHelper.CreateContext());

        result.Data.Should().Be($"one{Environment.NewLine}two");
    }

    [Fact]
    public async Task ExecuteAsync_ForMissingFile_ReturnsError()
    {
        var result = await _sut.ExecuteAsync(new FileReadToolInput(Path.Combine(_tempDirectory, "missing.txt")), TestHelper.CreateContext());

        result.IsError.Should().BeTrue();
        result.ErrorMessage.Should().NotBeNullOrWhiteSpace();
    }

    [Fact]
    public async Task ValidateInputAsync_WithEmptyPath_IsInvalid()
    {
        var result = await _sut.ValidateInputAsync(new FileReadToolInput(string.Empty));

        result.IsValid.Should().BeFalse();
        result.Errors.Should().ContainSingle("FilePath is required.");
    }

    public void Dispose()
    {
        if (Directory.Exists(_tempDirectory))
        {
            Directory.Delete(_tempDirectory, recursive: true);
        }
    }
}